swiss mod 89 load data

[CHEVELLE427]

looking for a starting point for an old mod 89 swiss 7.53x55 / 7.5x55, gun was made in 1883.

GP11 K11 K31 rounds are too hot.

I THINK THIS GUN TOOK GP90 AMMO THAT CANT BE FOUND

data i have found so far was 29gr semi smokeless with 200gr bullet

some have said load down to 30-40 krag

 

[rcmodel]

They used a paper patched .3208" bullet over 27 - 31 grains semi-smokeless powder.
Where you might find those I have no idea, as neither have been made for over 100 years. Reloading dies for the larger case neck of the paper patched round would also be a problem.

Pressure was supposed to be about 37,000 PSI, and even then, broken bolt lugs and bolts in the eye were problematic.

As a referance, 30-30 Krag is loaded to 40,000 CUP.
30-30 Winchester is loaded to 42,000 PSI.

rc

 

[CHEVELLE427]

looks like this will be having a lot of research to it.
the 7.5x55 GP11 will chamber and eject but a spent case wont chamber IN THE 89 as the K11 and K31 have a little more room for dirt and such i was also told

 

[jwr_747]

as far as chambering one rifles brass in another rifle,usually won't work.don't take much chamber difference to prevent chambering. zip over to the Swiss forum.they will get you headed in the right direction...jwr

 

[CHEVELLE427]

will give that a shot , i have been to the swiss site but most data stopped at the mod 89